focus

American  

[foh-kuhs] / ˈfoʊ kəs /

noun

PLURAL

focuses

PLURAL

focusses, foci

1. a central point, as of attraction, attention, or activity.

   The need to prevent a nuclear war became the focus of all diplomatic efforts.

   Synonyms:

   nucleus , core , heart , center

2. close attention or concentration.

   Some of the warning signs indicating you should pull over: drifting between lanes, repeated yawning, tailgating, and trouble maintaining focus.

3. the ability to concentrate one’s attention or to sustain concentration.

   Mindfulness and meditation are often suggested to help manage stress, increase awareness of emotions, and improve focus.

4. Physics.  a point at which rays of light, heat, or other radiation meet after being refracted or reflected.

5. Optics.

   1. the focal point of a lens, on which rays converge or from which they deviate.

   2. the focal length of a lens; the distance from a focal point to a corresponding principal plane.

   3. the clear and sharply defined condition of an image.

   4. the position of a viewed object or the adjustment of an optical device necessary to produce a clear image.

      in focus; out of focus.

6. Geometry.  (of a conic section) a point having the property that the distances from any point on a curve to it and to a fixed line have a constant ratio for all points on the curve.

7. Geology.  the point of origin of an earthquake.

8. Pathology.  the primary center from which a disease develops or in which it localizes.

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verb (used with object)

focused, focusing focussed, focussing

1. to bring to a focus or into focus; cause to converge on a perceived point.

   to focus the lens of a camera.

2. to concentrate.

   to focus one's thoughts;

   to focus troop deployment in the east.

verb (used without object)

focused, focusing focussed, focussing

1. to be or become focused.

   My eyes have trouble focusing on distant objects.

2. to direct one's attention or efforts.

   Students must focus in class.

focus British  

/ ˈfəʊkəs /

noun

1. a point of convergence of light or other electromagnetic radiation, particles, sound waves, etc, or a point from which they appear to diverge

2. another name for focal point focal length

3. optics the state of an optical image when it is distinct and clearly defined or the state of an instrument producing this image

   the picture is in focus

   the telescope is out of focus

4. a point upon which attention, activity, etc, is directed or concentrated

5. geometry a fixed reference point on the concave side of a conic section, used when defining its eccentricity

6. the point beneath the earth's surface at which an earthquake or underground nuclear explosion originates Compare epicentre

7. pathol the main site of an infection or a localized region of diseased tissue

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verb

1. to bring or come to a focus or into focus

2. to fix attention (on); concentrate

focus Scientific  

/ fō′kəs /

1. The degree of clarity with which an eye or optical instrument produces an image.

2. See focal point

3. A central point or region, such as the point at which an earthquake starts.

4. Mathematics  A fixed point or one of a pair of fixed points used in generating a curve such as an ellipse, parabola, or hyperbola.

5. The region of a localized bodily infection or disease.

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Usage

Where does focus come from? What does the word focus bring to your mind? Maybe you think of a photograph that is clear and sharply defined. Or perhaps you recall a teacher tsk-tsking you to pay attention in class. But what about a fireplace?Well, the word focus comes directly from the Latin focus, which meant “fireplace” or “hearth” (that is, the floor of a fireplace). This is what focus originally meant in English when the word entered the language around 1635–45, though that sense has been extinguished, as it were.But the word focus burned on in other ways. As the 1600s unfolded, focus was given new meanings in the great scientific literature of that age, which were largely written in what’s known as New Latin. In the 1650s, the influential English philosopher and author Thomas Hobbes used focus for a kind of fixed point in geometry. So did Isaac Newton—you know, of gravity fame—in the 1690s.Other applications of the word focus in the late 1600s came about in the fields of medicine and physics. In physics, a focus is “a point at which rays of light, heat, or other radiation meet after being refracted or reflected.” Perhaps you can imagine how a fireplace or a hearth—contained areas and sources of heat and light—was likened to such a point in math and science.Dig deeperThe word focus took on a number of senses in optics, specifically “the point on a lens on which rays converge or from which they deviate.” A more familiar sense of focus is “the clear and sharply defined condition of an image,” as when the image isn’t blurry. Optics has also given us the expressions in focus and out of focus, which can be used both literally and figuratively.From these various ideas of clarity and convergence in optics arises one of the more common, everyday ways we use the word focus today: “a central point, as a of attention, activity, or activity.” For example, Finding a cure for cancer was the focus of his long career. Focus also refers to ability to concentrate, as in The teacher felt the students struggled with their focus. These senses of focus had spread by the early 1800s, around when various verb forms of focus take off. The adjective form of focus is focal.

Other Word Forms

• focusable adjective
• focuser noun
• misfocus verb
• misfocused adjectivemisfocused, misfocusing
• misfocussed adjective
• overfocus verb (used with object)
• refocus verb
• self-focused adjective
• self-focusing adjective
• unfocusing adjective
• well-focused adjective

Etymology

Origin of focus

First recorded in 1635–45; Latin: “fireplace, hearth”

Example Sentences

It now has one site, focused mostly on commercial operations, with 1,200 employees.

From The Wall Street Journal

At my dad’s exit interview, his counselor advised him to keep Carville a secret so he could avoid the stigma it carried and focus on his life ahead.

From Salon

Nvidia is coming off a 62% year-over-year revenue increase in the latest quarter, largely stemming from its work on data centers, the backbone of the AI industry and a key focus for investors.

From MarketWatch

But on the credit front Morgan Stanley’s Lindsay Tyler was less encouraged in a note last week that focused on Oracle’s debt.

From MarketWatch

Many teams in that spot would simply have picked one of them to be their No. 1 and focused their resources on delivering him to the title.

From The Wall Street Journal

Related Words

• apply oneself to
• concentrate
• engage
• fixate
• pay attention to
• pore over